The present invention relates generally to an improved method and apparatus for the substantially continuous preparation of thermosetting plastic resinous products, and more particularly to such a method and apparatus which produces products having a composition which is substantially uniform, and which is dimensionally accurate and stable. The method and apparatus of the present invention provides a pair of in-line expansion chambers for the thermosetting products, with the first expansion chamber receiving the partially completely frothed material, and with the second expansion chamber being designed to receive the product in substantially completely expanded form.
In the preparation of frothed resinous products, particularly products made from thermosetting resinous materials, uniformity of composition, and uniformity and stability of dimensions are frequently desirable and in some cases, requisite. It is frequently desirable to extrude these foam products in order to achieve production efficiency, and when the composition may be maintained uniform, and the dimensions substantially constant, production can be maintained on a substantially continuous basis, and hence on an economically sound schedule.
Because of the rising costs of energy, particularly fuels used in heating of residential and industrial buildings, greater attention has been given to the utilization of thermosetting foams in the construction industry. Specifically, foamed-in-place resins have been recommended for utilization as thermal insulation, however these materials have not always been successfully installed. Problems arise due to overfilling or underfilling the voids, thereby establishing a thermal insulation layer or barrier having a density which is either unreasonably high or unreasonably low, thereby reducing the efficiency of the thermal barrier. It has been found that much of the volume ordinarily filled with foamed-in-place resin may be filled with solid rectangular frothed materials having a dimension matching that of the width, for example, of the volume to be filled. Ordinarily, the pre-formed thermosetting foams may be cut to desired length, and thereafter set in place.